Yo dudes, word up. Sorry it's been a while.

About a year ago, I hit a fox out on a KY highway (the fox was already dead). It was at night and the roads were slick so I couldn't jerk out of the way, so I had to hit it. With my 2 inch drop, hitting a dead fox on the road at 60 is about the equivalent of hitting a brick wall. Anyway, it messed up my gear cable or something and the car was jammed in 2nd gear.

Long story short, I was luckily 1/4 mile from my Uncles auto shop, and he fixed the cable the next day (its an automatic transmission, for the new guys that didn't know.) Ever since there has been this odd vibration in the floorboard between the accelerator and the center console when I kick it in. The car works perfectly but when I kick it in (pedal to the metal), when it gets in that high 2nd and low 3rd gear that vibration kicks in, and it almost sounds as if the car is hesitating or straining to give the wheels the power, and the car has little to no acceleration until the vibration works itself out (about five seconds with the accelerator all the way down), then the car continues to accelerate with no problems.

This hasn't happened at all before I hit that fox, and it is only until now (a year later) that the vibration has gotten more pronounced. The car isn't accelerating much in that high-2 low-3 gear, and its a Mustang; a Mustang without acceleration is like rock music without drugs.. so I'm really crossing my fingers. Fixing an automatic transmission can be costly.

Do any of you know what it could possibly be? Give it to me straight-out, no bullshit assessments. Appreciate it.